The present invention relates to a ballistic implant for successfully administering solid biologically active medicaments to domesticated livestock such as cattle and hogs, and in wild animals.
Solid dose ballistic projectiles shaped for penetrating the epidermal layer of living animal tissue are known. They lodge totally within the tissues of the animal for later release of biologically active medicaments into the animal""s tissue. xe2x80x9cSolid dosexe2x80x9d in this context therefore refers to the fact that the body of the projectile is made entirely of a mixture comprising biologically inert, usually soluble and/or biodegradable materials, encasing a biologically active medicament dose, commonly referred to as xe2x80x9cthe payloadxe2x80x9d.
Such bullets are used not only for domesticated livestock, but often for inoculating wildlife as well. They are particularly advantageous over administering typical liquid vaccines in that the animals do not have to be captured, thus avoiding the traditional time-consuming and costly necessity of gathering and treating the animals. Such herding also often causes animal stress resulting in weight loss, and even death in some animals.
Since it is well known that inoculations under physiological stress are often less effective than when applied to a relaxed animal, ballistic dose administration (using air guns to implant a medicament dose with a biologically inert bullet) has been developed. For examples of ballistic implants, see U.S. Pat. Nos. 3,948,263; 3,982,536; 4,326,524; 4,449,982; and 4,664,664. All of these have in common the use of a projectile, usually shot from an airgun. It penetrates, say 1-5 centimeters into the animal""s muscle tissue, where it begins to be reconstituted with the animal""s body fluids, usually disintegrating within a few hours, leaving no lasting tissue damage.
While ballistic implants have achieved some degree of success, due to their overcoming the need for gathering and herding of the animals, they have not achieved the degree of commercial success one might expect. This is so because of certain deficiencies, particularly in accuracy, with the currently-used ballistic implants.
Inaccuracy, that is, failure of the projectile to shoot where the gun is aimed causing xe2x80x9cmissesxe2x80x9d, wastes medicament, and therefore increases significantly veterinary medicine expense. Moreover, with poor accuracy there is a risk of bullets hitting the animal in areas where the bullet may cause harm (e.g., head, spine, thorax, chest), or in areas where the bullet will not successfully penetrate muscle tissue, such as forelegs and the like.
It can be seen, therefore, that there is a real and continuing need for the development of a ballistic implant of increased accuracy. Doing so would allow successful implanting of medicament at less expense without active drug waste. This invention has as its objective the fulfillment of this need.
A solid dose ballistic implant for vaccinating or medicating animals. It comprises a biologically inert tissue compatible bullet which defines an interior cavity having a wall with a frictionally enhanced engagement surface. A cylindrical medicament payload, slightly oversized with respect to the dimensions of the interior cavity, is force fit into the interior cavity, engaging the frictionally-enhanced cavity surface for a tight, secure fit. The resulting ballistic implants are of improved accuracy and can be successfully implanted into the flesh of an animal with greater reliability and less drug waste.